README
¶
limit
Go package limit provides a simple rate limiter for concurrent access.
Example middleware to limit HTTP requests:
import (
"github.com/pmorjan/limit"
"github.com/tomasen/realip"
)
func limitRequests(next http.Handler) http.Handler {
userLimit,_ := limit.New(1, 10) // 1 request per second, burst 10
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
ip := realip.FromRequest(r)
if !userLimit.Allowed(ip) {
http.Error(w, http.StatusText(http.StatusTooManyRequests), http.StatusTooManyRequests)
return
}
next.ServeHTTP(w, r)
})
}
Documentation
¶
Overview ¶
Package limit provides a simple rate limiter for concurrent access.
Index ¶
Examples ¶
Constants ¶
This section is empty.
Variables ¶
Functions ¶
This section is empty.
Types ¶
type Limit ¶
type Limit struct {
// contains filtered or unexported fields
}
Limit defines the limiter.
Example ¶
package main
import (
"fmt"
"net/http"
"net/http/httptest"
"time"
"github.com/pmorjan/limit"
"github.com/tomasen/realip"
)
func main() {
// middleware function
limitRequests := func(next http.Handler) http.Handler {
userLimit, _ := limit.New(1, 3) // 1 request per second, burst 3
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
ip := realip.FromRequest(r)
if !userLimit.Allowed(ip) {
http.Error(w, http.StatusText(http.StatusTooManyRequests), http.StatusTooManyRequests)
return
}
next.ServeHTTP(w, r)
})
}
handler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
w.Write([]byte("hello world"))
})
srv := httptest.NewServer(limitRequests(handler))
defer srv.Close()
// 4 requests
for i := 0; i < 4; i++ {
res, _ := http.Get(srv.URL)
fmt.Println(res.Status)
}
// next request after 1 sec delay
time.Sleep(time.Second)
res, _ := http.Get(srv.URL)
fmt.Println(res.Status)
}
Output: 200 OK 200 OK 200 OK 429 Too Many Requests 200 OK
Source Files
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